# dependencies
library(tidyverse)
library(scales)
library(stringr)
library(effectsize)
library(janitor)
library(knitr)
library(kableExtra)

Indiviudal differences scales - Bainbridge

  • N = 388
  • Worry ~ neuroticism, r = .85
  • Verbal aggression ~ agreeableness, r = -.61
  • Openness ~ need for cognition, r = .60

Correlation between weight and height in humans

in US adults, 2008-2012. NHANES CDC data.

library(NHANES)
data(NHANES)

dat <- NHANES |>
  filter(Age >= 18) |>
  filter(!is.na(Height) & !is.na(Weight)) 

ggplot(dat, aes(Weight, Height)) +
  geom_point(alpha = 0.1)

ggplot(dat, aes(Weight, Height)) +
  geom_point(alpha = 0.1) +
  facet_wrap(~ Gender)

dat |>
  summarize(n = n(),
            cor = broom::tidy(cor.test(Weight, Height, use = "pairwise.complete.obs"))) |>
  unnest(cor) |>
  select(n, r = estimate, ci_lower = conf.low, ci_upper = conf.high) |>
  mutate_if(is.numeric, janitor::round_half_up, digits = 2) |>
  kable() |>
  kable_classic(full_width = FALSE)
n r ci_lower ci_upper
7414 0.45 0.43 0.47 
dat |>
  group_by(Gender) |>
  summarize(n = n(),
            cor = broom::tidy(cor.test(Weight, Height, use = "pairwise.complete.obs"))) |>
  unnest(cor) |>
  select(n, r = estimate, ci_lower = conf.low, ci_upper = conf.high) |>
  mutate_if(is.numeric, janitor::round_half_up, digits = 2) |>
  kable() |>
  kable_classic(full_width = FALSE)
n r ci_lower ci_upper
3763 0.28 0.25 0.31
3651 0.39 0.36 0.42

Difference between average height of adult men vs women

dat <- NHANES |>
  filter(Age >= 18) |>
  filter(!is.na(Gender) & !is.na(Height) & !is.na(Weight)) 

dat |>
  summarize(n = n()) |>
  kable() |>
  kable_classic(full_width = FALSE)
n
7414

Weight:

effsize::cohen.d(Weight ~ Gender, data = dat)
## 
## Cohen's d
## 
## d estimate: -0.6685073 (medium)
## 95 percent confidence interval:
##      lower      upper 
## -0.7152995 -0.6217151

Height:

effsize::cohen.d(Height ~ Gender, data = dat)
## 
## Cohen's d
## 
## d estimate: -1.869864 (large)
## 95 percent confidence interval:
##     lower     upper 
## -1.924451 -1.815276